Felting for surgical splints



llwrrnn rates WILLIAM H. JOHNSTONE, OF PHILADELPHIA, PENNSYLVANIA.

FELTING FOR SURGICAL SPLINTS.

SPECIFICATION forming part of Letters Patent No. 226,076, dated March 30, 1880.

Application filed March 10, 1880. (No model.) I

To all whom it may concern:

Be it known that I, WILLIAM HAMPDEN JOHNsToNE, of Philadelphia, Pennsylvania, have invented certain new and useful Improvements in Felting for Surgical Splints; and I do hereby declare the following to be a full, clear, and exact description of the same.

The nature of my invention will appear from the following specification and claims.

The object of my invention is to produce a compound felt consisting of several fibrous layers or laps, and is especially designed for use in the manufacture of surgical splints, surgical jackets, corsets, and the like. The object of using several layers or laps in forming my com pound felt is that I may be able to have it more closely felted upon that surface of the felt which is designed to be worn next to the skin when the felt becomes a splint, and I felt more loosely the layer which adjoins the surface layer above spoken of. The several layers are felted together so as to cohere, thus forming a compound felted fabric of several layers. This fabric is then saturated with shellac or some other stiffening agent, and is then ready to be shaped into a splint, jacket, or corset. After saturation it is rolled between rollers, (cold.) The shellac will then be found to have taken refuge in the interior that is, its great mass will reside in the looselyfelted lap, leaving the above-named closelyfclted surface lap comparatively free from the solution and of a soft woolly surface.

There are many processes of felting fibers of material in layers so as to form a finished fabric of felt-cloth; and while I do not limit myself to the precise method herein described, I will describe one of these processes, together with the other parts of my invention, so as to enable others skilled in the artto make and use the same.

My compound fabric is composed of several sheets or layers, and is formed in the following manner: It is well known to felt manufacturer; that the better qualities of felt are made of pure woolen fiber. By means of a carding-engine I first form a lap of longfibered wool, this lap being usually about twenty yards wide and two yards long. As it comes from the card it is laid out flat on a long platform or apron in front of the doffer of the card. I then card out a thicker lap of thus have the thick lap of short fiber between them. The three laps thus arranged may be said to form a compound lap. This compound lap is then rolled up, soaked in heated water, and is pounded and treated in the manner usually employed in felting various layers of fiber or laps. The fibers composing the contiguous surfaces of the adjoining laps become felted together, as well as the fibers composing each lap, so that when the felting operation is completed the compound lap abovedescribed becomes a homogeneous felted fabric. As the inferior short-fibered wool of the interior lap will not felt so densely as the longer-fibered wools, the interior of the felted fabric thus formed will be more open or less dense than it is upon the surfaces, as the inner layer will felt less closely than the outer ones.

My felt is not made so dense as that used in hat-bodies, but is more open, soft, and porous throughout.

To make the splint, the felt is then stiffened with some solution having that efi'ect, such as shellac, which I use in my manufacture. I cut a piece of my compound felt to about the size required for the desired purpose, and saturate it thoroughlyin 'a solution of shellac and alcohol. Now, as the interior of this felt is more loosely felted than the outer layers, the middle will receive and retain by absorption more of the shellac than the outer parts or layers. I then pass the piece through two cool calender-rolls set to such a distance apart as is equal to about the thickness of the interior layer of the felting-that is, of the interior lap. This rolling of the saturated fabric has the effect of equalizing the distribution of the shellac and of compressing nearly all of it out of the exterior laps and forcing it into the interior lap, leaving the outer layers soft and smooth. The material must then be thoroughly dried. It is then placed in a steambox and softened.

The action of the steam is much superior to that of the hot-water bath, for the latter is apt to cake the shellac and run it together in places in hard masses, while steam gently softens it and does not destroy the porosity of the fabric.

The felt thus softened can be molded to almost any shape and to fit any irregular form, whether used as a splint in surgery or otherwise, and after being so molded and allowed to harden it will retain rigidly the shape so given to it. Its surface will be soft and pleasant in contact with the skin.

In rolling the material I use cold rolls, so as not to make the shellac too thin. If thin it has a tendency to run in irregular masses. The distance apart of my rolls is such that the felt upon leaving them is so relieved that the spring and life of the long outer fibered laps tend to lift them away from the comparatively inert inner lap, leaving the latter to hold the main part of the solution.

1 make my central layer of a thickness about equal to that of the other two layers combined.

In preparing my stiffening solution, I use a proportion of about four pounds of shellac to one gallon of alcohol.

I usually cut a complete set of splints, consistin g offifty pieces, from twenty-eight square feet of felt, and that much of my compound felt I allow to take up in saturation about one and one-fifth gallon of the solution. 'lhat quantity of felt will make two sets of splints, one for an adult and one for a youth, each set consisting-of twenty-five pieces.

Heretofore hot irons have been used to iron the fabric after it has been saturated with the shellac; but this course thins the shellac by melting, and results in making the surface of the felt hard and caked in spots. My use of cold rolls removes this difficulty.

My application for a patentfiled June 23, 1879, claims and describes a compound felting formed of two or more layers of felted material, one layer being formed of shorter fiber than the others. In it is also claimed the process of first saturating a fabric for use in splints in shellac or its equivalent, and then passing it between two rolls to evenly distribute the shellac and drive it into the interior of the fabric. Said application also describes and claims, broadly, such afabric (compound fabric) saturated in a solution of shellac or its equivalent, and therefore these devices are not clai med herein as part of this invention.

Another method of felting one layer more loosely than another is as follows: I take one thin layer of closelylapped wool from the card and lay it out, as already described. I then lay upon this one a second lap much thicker than the first, but more loosely lapped upon the lap-machine, or it may be more loosely carded. Then over this I place another lap like the first. All three laps may, if desired, be of the same quality of wool. The whole is then felted, as already described. It will then be found that the innerlayer is more loose and open than the two outer ones, and when the fabric is soaked in the shellac the mass of the latter will be held in the middle of the fabric.

My treatment of the finished fabric when saturated with the shellac is always the same. I pass it between the cold rolls to produce a material out of which my splints, 850., can be made, and my whole object is to produce a material the best adapted for this purpose.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A compound felting formed of two or more layers of felted material, one layer being felted more loosely than the other, substantially as described.

2. A compound felting formed of three layers of felted material, the two outer layers being more closely felted than the interior layer, substantially as described.

3. The process of preparing the fabric for formation into a splint or jacket by first saturating it in a solution of shellac or similar material, drying it, and thensteaming it to soften it, substantially as described, and for the purposes set forth.

4. The process of preparing a fabric for use in splints by first saturating it in a solution of shellac or its equivalent, and then pressing it between two cold rolls, whereby the shellacis evenly distributed and is driven into the interior of the fabric, substantially as described.

5. In preparing a fabric for a use in which great stiffness is desired, the process of steeping or saturating it in a stiffening solution, substantially as above set forth, then passing it between two rolls adjusted to a distance apart equal or about equal to the thickness or space within which it is desired to retain the stiffening compound, whereby the surfaces of the fabric are kept comparatively free from the said solution, substantially as and for the purposes described.

6. A compound stiffened felting for splints or jackets formed of two or more layers of felted material, one layer being felted more loosely than the other, the whole being stiffened by a solution of shellac, with which it is saturated, substantially as and for the purposes set forth.

WM. HAMPDEN J OHN STON E.

Witnesses:

FRANCIS D. PASTORIUS, HENRY B. Column. 

